docs: def parse_bytes(field):
      '''
      >>> parse_bytes('24B')
      24.0
      >>> parse_bytes('4MiB')
      4194304.0
      '''
      if field[-1] in 'bB':
          field = field[:-1]
  
      try:
          for i, prefix in enumerate('KMGTPEZ'):
              if field.endswith(prefix + 'i'):
                  factor = 2 ** (10 * (i + 1))
                  return float(field[:-2]) * factor
  
          return float(field)
      except ValueError:
          return None